[Express.js] Get raw Data from req.on when you use body-parser

middleware.js

/*
	`app.use(bodyParser.json())`
	`Content-Type=application/json`
	BodyParser will parses json data correctly
	And cleanup() from raw-body, a dependency of body-parser will clean-up the raw data
*/

function cleanup() {
	received = bufer = null
	stream.removeListener('data', onData)
	stream.removeListener('end', onEnd)
	stream.removeListener('error', onEnd)
	stream.removeListener('close', cleanup)
}

/*
	It will lead to `on` and `end` event won't be executed
	So, if want to get raw-data from request, you need to do
*/

app.use(function(req, res, next){
	const reqData = []
	const size = 0
	req.on('data', data => {
		reqData.push(data)
		size += data.length
	})
	req.on('end', () => {
		req.reqData = Buffer.concat(reqData, size)
	})
	next()
})

app.use(bodyParser.json())
app.use(bodyParser.urlencoded())

// https://www.cnblogs.com/hubcarl/p/4066183.html